Backup servers may be part of the master piece in data protection suite. Usually, back up servers are responsible for ensuring smooth operations backup related operations such as scheduling, controlling and monitoring of backup, recovery and replication jobs; server maintenance operations (e.g. catalog maintenance and garbage collection); maintaining integrity of backup operation related data (e.g. catalog database or catalog directory) to avoid data corruption; resource allocations, authentication and authorization; and disaster recovery operations, etc. The backup server has to be more resilient and responsive to ensure successful completion of these operations which could be sequential or concurrent in nature.
Under normal conditions, operations are performed with concurrency that does not have backup server impact and remaining operations are sequentialized. However, busy environments can result in higher concurrency of operations that cause stress and load on the backup server. As a result, contention to access the backup operation related data (e.g. catalog database) among these operations may arise, even if processor resources and memory usage are properly allocated to perform these operations. Backup operations may hang or even abort (e.g. due to timeout settings) with serious contentions. Typically this is handled with built-in operation retry mechanism that hides the operational failures from end-user, but does not solve the actual problem.